Given these parameters, we find the total noise budget agrees with the measured spectrum for most frequencies. At low frequencies, the experiment is limited by seismic noise, hence the additional noise in the measurement with respect to the blue curve in Figure REF . In theory, it is possible to lock a Fabry-Perot cavity like this one without the use of feedback, instead using a large, positively detuned carrier beam and a small, negatively detuned sub-carrier beam [1]}, [2]}. This has been tested to show the stability of the double optical spring effect, but not yet on its ability to stabilize the power of the laser. In this regime however, it would be possible to lock the cavity and have the power stabilized without the use of feedback anywhere.
